The present invention relates to wireless communication technology, and, more particularly, to methods of operating multi-mode mobile terminals and related mobile terminals and computer program products.
Battery technologies are advancing to provide more capacity per unit volume. As a result, the end point voltage is often lower for these newer types of batteries. When used in electronic devices, such as mobile terminals, these batteries may introduce a new design constraint. Many mobile terminals can be made to operate on voltages of 1.8 volts or lower. It is expected that, in the future, most logic may be able to operate on less than one volt. In a mobile terminal, however, the Radio Frequency (RF) power amplifier may be difficult to design for operation at lower voltages. The decreasing efficiency of the matching network as it connects lower impedances to 50 ohms as the operating voltage decreases and operating current increases may limit the acceptable operating voltage to some value related to the maximum output power level. Typical RF power amplifiers deliver full output power at 3.4 volts, which is the minimum operating voltage for many conventional batteries. Many battery technologies may deliver the full battery capacity between about 4.2 volts and 2.4 volts. The discharge curve, however, generally demonstrates more slope from fully charged to fully discharged in contrast with older battery technology that often included a relatively large plateau region in the discharge curve.